Removes the non-standard -webkit-perspective-origin-[x,y] properties. Note however that the -webkit-perspective-origin property (an alias of perspective-origin) is not affected.
The -webkit-perspective-origin-[x,y] properties overlap in a non-trivial way with another standard property (perspective-origin). This situation is not supposed to exist, and therefore the interaction -webkit-perspective-origin-[x,y] and perspective-origin is not defined by any spec.